1. Technical Field
The present invention relates to a driving method for a CCD type solid-state imaging device and an imaging apparatus, and in particular, to a driving method for a CCD type solid-state imaging device and an imaging apparatus, which are capable of reading dynamic image data in a wide dynamic range from imaging devices.
2. Related Art
Patent Document 1 (JP 2004-55786 A corresponding to US 2004/017497 A) discloses a CCD type solid-state imaging device in which approximately half of the pixels provided in the form of a two-dimensional array on a semiconductor substrate are made into high sensitivity pixels having a large area, and approximately the remaining half are made into low sensitivity pixels having a small area. Using the CCD type solid-state imaging device, taken image data read by the high sensitivity pixels are synthesized with taken image data read from the low sensitivity pixels, whereby it is possible to attempt to secure a wide dynamic range of taken images.
Also, Patent Document 2 (JP Hei. 9-252107 A) discloses a CCD type solid-state imaging device, in which two types of photoelectric converters are provided, capable of varying the respective charge accumulation times thereof. Even in the CCD type solid-state imaging device, it is possible to cause taken images to be brought into a wide dynamic range by synthesizing output signals of two types of photoelectric converters.
In Patent Document 3 (JP 2007-124137 A), two types of pixels that vary charge accumulation times by a CMOS type solid-state imaging device are mixedly provided on a semiconductor substrate, and it is possible to cause taken images to be brought into a wide dynamic range by synthesizing taken image data read from each device.
Where high sensitivity pixels of a large area and low sensitivity pixels of a small area are mixedly provided on a imaging device, the range magnification of the dynamic range will be predetermined by the area ratio, etc. There is a problem that any optional range magnification is not obtainable.
Further, in the case of a CMOS type, although it is easy to vary the charge accumulation time of pixels, there is a problem that, in the case of a CCD type, it is not easy to optionally vary the charge accumulation times for pixels for taking high sensitivity images and for pixels for taking low sensitivity images, which are mixedly provided on a semiconductor substrate, where a dynamic image is picked up without using a mechanical shutter, that is, where carrying out progressive (non-interlace) reading but not an interlace reading (multi-field reading).
Therefore, it is an object of the present invention to provide a method for driving a CCD type solid-state imaging device and an imaging apparatus, which are capable of obtaining dynamic image data in a wide dynamic range.